California Faults and Seasonal Stress (IMAGE) University of California - Berkeley Caption Faults throughout central and northern California are shown with the stress change induced by the hydrological loading cycle. Depicted are the stresses during the dry late summer months, when minimal water is stored near the surface, and during the early spring when maximum water is stored following the winter months. The seasonal change in water mass deforms the crust, changes stress on faults and modestly modulates regional small earthquake. The faults located to the west of the Central Valley belong to the San Andreas Fault system and more favorable faulting conditions are during the dryer summer months. The Eastern California Shear Zone faults to the east of the Sierra Nevada are more loaded during the wet winter months. Credit Image produced by Christopher Johnson, Berkeley Seismological Laboratory, UC Berkeley Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.